The new e-flite electric retracts come in a size that is suitable for size 10 to 15 aircraft. They say that that is an airplane up to 4.5 pounds. What is the definition of a 10 to 15 airplane and a 60 to 90 airplane. I understand that it was originally based on engine size.

In the electric EDF jets there is a very large jet called the Eurofighter. It weighs 5 pounds. Since the jets have smaller wheels, would the size 10 to 15 retracts be suitable for this large jet? Thanks

It is kinda based on engine size and weight a 10 -15 size plane will weigh around three pounds with a wing span up to 48 inches, while a .40 size will weigh up to 5 lbs with a span up to 60 inches, .60-.90 from 6 to 10 pounds. There are also many factors involved, wing design, airplane construction. Take a look at the Peace-O-Cake and the Butterfly Huge wingspans but they take a .049 and a .15. Some of the Warbirds that have a 60 inch span might take a 90 to 120. It will also depend on what class of airplane, whether it is a Sport model, or a 3D, or scale. Today's 3D airplanes are very light weight and are powered to have unlimeted vertical performance, sport planes like a goldberg Falcon or Great Planes Sportster are not.

Back to the main question when purchasing retracts take engine size and weight into consideration.

I'd put a 10-15 size plane in the 2lb range...

My .25 - .32 size electrics go from 3 to 4lbs